Hardware Assisted PMU Virtualization

on YouTube ↗26m

" summary

Hardware-assisted PMU virtualization extends the upstream Mediated PMU framework with automatic save/restore of guest PMU state in hardware, direct interrupt delivery to guests (avoiding NMI injection round trips), and a hardware-enforced allowlist for perf MSRs that dramatically cuts VM exits. It also virtualizes IBS (instruction‑based sampling) to deliver precise RIP and fetch/op samples in‑guest, enabled real fixes (e.g., removing a legacy dummy wait) and ships RFCs and patches upstream for evaluation.

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" chapters (15)

1. 0:00Hardware assisted PMU virtualization
2. 1:03Emulated vs mediated PMU
3. 3:14Key PMU concepts
4. 6:49Mediated PMU lifecycle
5. 8:13VPMC with hardware assist
6. 10:48Why intercept perf control MSR
7. 12:38Direct interrupt delivery
8. 14:03Instruction Based Sampling overview
9. 16:34IBS performance example
10. 17:37IBS virtualization workflow
11. 19:46PMU filtering
12. 22:13PMU methods comparison
13. 23:38Confidential guest PMU security
14. 24:40Status and upstream patches
15. 25:01Q&A

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